Raising a pier and beam house with problems

Ok I just realized that I posted this in the wrong dang forum on accident, so let me try again.
I am working on a small 600 sq. ft pier and beam house that has some major problems. The structure consists of a main part that measures 24'x24' and an addition to one side that measures 10'x20'. I want to try to do the entire job myself due to the fact that money is really tight right now, and I feel that the building is small enough that it is possible.
For starts, the entire structure needs to be raised about 2 ft. The problem is that there is a large portion of the house that is directly on the ground due to either the person that built it not building it high enough or the piers sunk into the ground because it wasn't prepared right.
To make it more difficult the floor framing was not built right according to what my experience tells me. Instead of having a sill beam, then floor joist framing, the builder simply put his end joist across the pierstones. This has led to the end joist rotting on one side and the subfloor sitting on the piers. Of course this is the side that is sitting on the ground.
So... Here are my questions. First how do I gain access to underneath the house where it is sitting on the ground without having to tunnel completely under the house?

Second does anybody have any experience raising a small house like this and how did you do it?

Third should I correct the foundation framing in the process of raising and leveling the house?

Four In all who answers opinion when is a house just too far gone to save?

I've seen restorations where it appears that the entire floor framing is removed and replaced. While not worthy of being a "restoration" that might be the technique I need to use in order to save this house. How do they do that without losing structural integrity of the building?

We see this question alot. The problem is, there are no quick fixes. Each home is different and really needs evaluation from an engineer.
good luck

I've got a house built on pier and beam sometime between 1940-50 in North TX, where the soils 'move'. It does dip going down the hall to the back bedroom. Have had several inspections and several bids. Some inspectors don't even comment, some make it sound as if the house will cave tomorrow, if not sooner. Bids have ranged from 2,500 to 10,000. Most bid some form of lift and shim at a minimum to a whole new set of piers bored down to a minimum depth, however deep it may be, to soil containing < 2% moisture. Regardless of the original bid, every contractor, when I said no to the original bid, offered to do a "quick fix for 1,000 to 1,500 that might actually be all I need - after all, the house is 50+ years old." When asked what it was, it was a jack and shim the low spots and maybe cut into the beams so they lower onto the piers where high. Not to slam the integrity of contractors, but how I am I suppossed to make an informed decision here?